With the advent of television in the late 1930s, a succession of images were produced with a raster scanning television camera. Transmitted to television viewers as analog radio signals, the images were recreated by a synchronized raster scanning cathode ray whose beam impinged on the back side of a vacuum tube covered with fluorescent dots. Each dot provided a single element of the recreated images. In digital imaging, a pixel is a physical point in a raster image, or the smallest addressable element in an all points addressable display device. Thus, it is the smallest controllable element of a picture represented on a screen. The word “pixel” is a portmanteau of pix (from “pictures”, shortened to “pics”) and el (for “element”). The word was first published in 1965 by Frederic C. Billingsley of JPL, to describe the picture elements of video images from space probes to the Moon and Mars. Billingsley claimed to have learned the word from Keith E. McFarland, at the Link Division of General Precision in Palo Alto, who in turn said he did not know where it originated. McFarland said simply it was “in use at the time” (circa 1963).
Although there remain some very vocal analog holdouts in audio and photography who insist that vinyl records and film are respectively better reproduction media, we now live in a world that is largely digital. By failing to anticipate the rapid transition to digital photography, while at the same time attempting to maintain its virtual monopoly on the film photography market, Kodak Corporation was forced to file for bankruptcy protection in January 2012. Although the company has since emerged from bankruptcy, it is now only a shadow of what it was in its glory days during most of the twentieth century.
Very large, freeway signboard size flat panel displays are now used extensively for advertising in large cities. Such flat panel displays are even more ubiquitous in present-day China. These, of course, are digital displays in which all pixels are addressable. The displays are capable of displaying graphic images in either still or video format.